antlr4 How to fix lexer mode implicit token error?

[garym]

I have a token collision with some text and was thinking about using lexer modes to work around the issues.

I create the mode in the Lexer file, but when I complie the Parser file I get the following warnings:

warning(125): TSqlParser.g4:2377:26: implicit definition of token DISK in parser
warning(125): TSqlParser.g4:2377:31: implicit definition of token TAPE in parser
warning(125): TSqlParser.g4:2377:36: implicit definition of token URL in parser

How can I fix this ?

My mode definition are:

BACKUP:                                'BACKUP' -> pushMode(BackupTokens);

mode BackupTokens:
DISK:                                  'DISK' -> popMode();
TAPE:                                  'TAPE' -> popMode();
URL:                                   'URL' -> popMode();